PURPOSE: Conservative management has been largely used for renal trauma. Although this approach is safe and highly recommended, it can hide a pre-existing unknown condition, such as tumors or urinary malformations. A high index of suspicion is needed for early recognition of these conditions. We present four cases treated at the Pediatric Oncology Institute - Federal University of São Paulo, which have been initially treated conservatively for renal trauma. MATERIALS AND METHODS: We reviewed all 218 renal cases of renal tumors treated at our institution in a 22-year period, searching for associated trauma events. RESULTS: Four cases of renal tumors were initially treated conservatively for blunt renal trauma of low energy mechanism. Patients' ages ranged from 7 to 12 years old. Two patients had no previous symptoms, one patient had hematuria and another had an abdominal mass. Computerized Axial Tomography (CT) of the abdomen revealed disparate magnitude of the renal bleeding to the low energy mechanism of trauma. All patients underwent surgical treatment. Kidney specimens showed Wilms tumor in three cases and renal carcinoma in one. CONCLUSIONS: The association between renal tumors and trauma should be suspected when renal trauma hemorrhage on abdominal CT scan does not match the low energy mechanism of blunt abdominal trauma. The key for a successful diagnosis of renal tumor or congenital malformations is the high index of suspicion for these conditions.

CONTEXTO E OBJETIVO: Os cateteres de longa permanência totalmente implantáveis (por exemplo, Port-a-Cath®) são muito utilizados para acesso venoso de longa duração em crianças com câncer. O uso deste tipo de cateter está associado a algumas complicações como infecção, extrusão, extravasamento e trombose. A embolia de fragmento de cateter é complicação rara, mas com potencial morbidade. O objetivo do estudo foi relatar dois casos em que houve embolia de fragmento de cateter de longa permanência. TIPO DE ESTUDO E LOCAL: Série de casos do Hospital do Servidor Público estadual, São Paulo. MÉTODOS: Estudo retrospectivo das embolias de cateter de longa permanência em crianças. RESULTADOS: No primeiro caso, descreve-se uma menina com diagnóstico de tumor de Wilms estádio IV aos três anos de idade. Iniciou tratamento com implante de cateter de longa permanência em veia subclávia. Três anos após diagnóstico, foi programada a retirada do cateter por término de tratamento. No momento da retirada, houve fratura intracardíaca do cateter. Houve necessidade de retirada do fragmento intracardíaco com hemodinâmica. O segundo caso tratava-se de um menino com diagnóstico de tumor de Wilms estádio II aos dois anos de idade. Teve o cateter implantado no início do tratamento. No momento da retirada por fim de tratamento, o cateter já havia desconectado e embolizado. O fragmento intracardíaco foi retirado também por procedimento de hemodinâmica. CONCLUSÃO: A embolia de fragmentos de cateter em cateteres de longa permanência é uma complicação rara, mas que necessita ser reconhecida, mesmo em pacientes assintomáticos.

CONTEXT AND OBJECTIVE: Long-term totally implantable catheters (e.g. Port-a-Cath®) are frequently used for long-term venous access in children with cancer. The use of this type of catheter is associated with complications such as infection, extrusion, extravasation and thrombosis. Embolism of catheter fragments is a rare complication, but has potential for morbidity. The aim here was to report on two cases in which embolism of fragments of a long-term totally implantable catheter occurred. DESIGN AND SETTING: Case series study at Hospital do Servidor Público Estadual, São Paulo. METHODS: Retrospective review of catheter embolism in oncological pediatric patients with long-term totally implantable catheters. RESULTS: The first patient was a 3-year-old girl diagnosed with stage IV Wilms' tumor. Treatment was started with the introduction of a totally implantable catheter through the subclavian vein. At the time of removal, it was realized that the catheter had fractured inside the heart. An endovascular procedure was necessary to remove the fragment. The second case was a boy diagnosed with stage II Wilms' tumor at the age of two years. At the time of removal, it was noticed that the catheter had disconnected from the reservoir and an endovascular procedure was also necessary to remove the embolized catheter. CONCLUSION: Embolism of fragments of totally implantable catheters is a rare complication that needs to be recognized even in asymptomatic patients.